Reinforced insulation assembly



Patented Sept. 25, 1951 REINFORCED. INSULATION ASSEMBLY Merle- E.Barnhart-and Lee F. Miller, Frederick, Md., assignrs-t0 Price ElectricCorporation, 1 Frederick, Md a corporation of Maryland Applicationqlune10, 1946, Serial N 0. 675,792

2 Claims.

This invention has to do with the reduction of the number of parts to beput together in the final groupings, while contributing to the hold-upproperties or physical strength of the elements in the handling, as wellas the final groupings thereof.

This invention has utility when incorporated in insulation forelectrical devices, as for wiring coil mountings or bobbins, moreparticularly wherein the spool ends or disks comprise insulation facedmetal.

Referring to the drawings:

Fig. I is a fragmentary, somewhat schematic showing, the plies beingsomewhat out-of-proportion in thickness, of the bonding, effectedsimultaneously with the forming, of spool end washers or disks withinsulation facing therefor;

Fig. II is a plan view of a bonded strip as excess from the articlesproduced by the punching operation of Fig. I;

Fig. III is an enlarged detail, partly in section of a metal body, facedwith a. pressure sensitive adhesive insulation;

Fig, IV is a plan view of the disk of Fig. III, parts being broken away;

Fig. V is a detail, with a portion broken away, of a spool bodyinsulation tube or straw, say of acetate, or acetate coated;

Fig. VI is a completed bobbin, partly in section, of a magnetic corethru the straw, assembling the washers thereon to complete the spool toreceive an electric winding;

Fig. VII is a side elevation of an insulation body for receiving a coil,having the disk feature at one end and a more heavy insulation base atthe other; and

Fig. VIII is a view from the right of the body of Fig. VII, with aWinding thereon, in readiness for lead connections thereto.

A supply of strip stock I may be from a roll or in lengths. The stock Iis desirably of nonmagnetic material and may be in the range of ,4,thickness when say not exceeding 1" in width. A roll 2 of acetate filmtape body, or coated with pressure sensitive adhesive 3 as the stock ortape 4 is unwound to have the adhesive 3 ride against a side of themetal body I in passing to a punch press 5 having a cutting rim I5 andconcentric therewith a cutting stem 1.

The punch press effects bonding between the metal strip I and the tape 4into a unit of two joined laminations 8 having openings 9 therethru. Thepassing-along strip 8 may be considered as scrap, or stock excess fromthe cut- '2 ting of the minor rejectdisk II) and a ring product II.

The punch press operation has peripherally squeezed the coated tape intoan effective bonding rim I2, as well as a slightly less pronouncedconcentric inner region I3 about the opening I4. The product or disk I Ithus comprises an insulation face I5 having its coated inner faceagainst an assembled-therewith reinforcing body III, which may have analmost insignificant marginal burr or offset I'I. Notwithstanding thethin metal sheet of the body I6, it is of flat form retaining rigidity,in fact somewhat stiffened.

The preassembly unit or disk II which forms the flanges of the spool mayhave its insulation faces I5 toward each other as concentric with aspool body or insulation straw I8 therebetween, of similar insulationcharacteristic. An electromagnet core I9 extends thru the openings I4and the intermediate tube I8, has at one end an armature head 20, and atits opposite end a rivet 2|. The bobbin or spool is thus grouped withfew parts to be handled, and all in definite accuracy or alignmentregister. The product is of light weight and considerable physicalstrength, with a safety factor beyond demands to be met in normalservice.

The assembled spool end or disk II on a tube I8 may be mounted on aninsulation base 22 of rigid plastic or fiber. The assembly is by anelectromagnet core 23 and a rivet rim 24. The more heavy base spool unitmay have a winding 25 thereon with terminal 26, 21. The base 22 may haveledges 28 with openings 29 therethru for terminal screws, or coilmounting.

It is to be noted that the pre-assembly of the reinforcement with theinsulation, besides reducing the number of parts to be handled in thefinal assembly, insures accuracy of register or alignment between themetal body or base and the insulation film or tape washers of the twoplyunit.

The pressure bonded unit may be generally characterized as a two-plysheet, with electrical adaptation possibilities, not only for thewashers or the spool ends but terminals having a conducting face and anopposite insulation face, as fixed or rigid, and as spring arms orcontacts, and generally in switches and windings.

In the instance of acetate or like fungus resisting insulation material,there is adequate protective resistance to such attack, in thepressurebonded two-ply unit herein. The reduction of the number of partsto be put together, reduces the assembly time, and thereby cheapensproduction. The wafer-like body of the flange ply reinforcement also hasimportance in increasing the space available for winding with adequatephysical strength for the assembly and use. This means that the windingsproper may occupy the major volume and the space requirement for theinsulation carrier therefor is an almost negligible minimum.

What is claimed and it is desired to secure by Letters Patent is:

1. A spool for an electric coil, said spool comprising a magnetic metalcore, an insulation tube on said core, and flanges on said tube, atleast one of said flanges comprising a metal annular disk and an annularinsulation disk adhering to said metal disk by an adhesive layer, saidinsulation disk being beveled against the outer periphery of said metaldisk to form a tight rim seal between said insulation disk and saidmetal disk.

2. The spool of claim 1 wherein said insulation disk comprises anacetate film.

MERLE E. BARNHART. LEE F. MILLER.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 931,541 Wohl et a1 Aug. 17, 19091,208,577 Kraemer Dec. 12, 1916 1,236,357 Reeve Aug. 7, 1917 1,282,380Cotterman Oct. 22, 1918 1,659,062 Varley Feb. 14, 1928 2,180,420 LarsenNov. 21, 1939 2,226,589 Smyers Dec. 81, 1940 2,247,252 Price June 24,1941 2,264,628 Engert et al Dec. 2, 1941 2,300,072 Smyers Oct. 27, 19422,375,330 Sperry May 8, 1945

